Last updated: June 2, 2025
In Crystal Lake, understanding the UV Index is crucial for maintaining skin health and preventing sunburn, especially during the warm months. The UV Index measures the strength of ultraviolet radiation from the sun, which can be quite intense in this Cfa climate zone. With peak values reaching as high as 12 between 12 PM and 1 PM, residents and visitors must be vigilant about sun exposure to protect themselves and their families. By staying informed about UV levels, you can enjoy the outdoors safely while minimizing the risk of harmful effects from the sun.
The day begins gently with a UV Index of 1 at both 07:00 and 08:00, indicating minimal sun exposure. However, as the clock strikes 09:00, the index rises to 3, signifying a gradual increase in UV intensity. By 10:00, it reaches 5, and the sun takes center stage at 11:00 with a striking 8. The peak arrives at 12:00, soaring to an impressive 10, and continues to climb, hitting its pinnacle with a dazzling 12 at 13:00. As the afternoon unfolds, values begin a slow descent: 11 at 14:00, 10 at 15:00, and then dropping to 7 by 16:00. The evening brings relief, with the index tapering down to 4 at 17:00, 2 at 18:00, and finally returning to a safe 1 by 19:00. Remember to stay protected during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index demonstrates significant seasonal variation, reaching its peak during the summer months of June and July, with an extreme UV Index of 12 and a burn time of just 10 minutes. The high-risk months for UV exposure extend from February through September, where values consistently register high to extreme levels. Specifically, April and May see sustained extreme conditions with an index of 11, indicating that extended outdoor activities should come with caution. Residents and visitors are advised to take proactive measures by seeking shade, wearing protective clothing, and applying sunscreen regularly during these high-risk months, particularly from March through September when the potential for harmful UV exposure is greatest. As we move towards October and November, UV levels decrease, allowing for safer outdoor activities, although awareness should always remain a priority.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |
| Crystal Lake | 6 | 8 | 10 | 11 | 11 | 12 | 12 | 11 | 11 | 9 | 7 | 5 |